Transient Non-Suppressible Cough at Altitude Occurring With Cessation of Exercise

Abstract

The aim of this report is to describe two subjects with an uncontrollable dry cough that occurred at altitude immediately after cessation of intense exercise; the cough occurred at 5 - 15 second intervals and resolved in 20-30 min with rest or a reduced level of exercise. The presence of cough did not foreshadow an increased risk of acute mountain sickness (AMS) or high altitude pulmonary edema (HAPE) and, in a third subject, was observed to occur at sea level. Its etiology is uncertain but it is probably not related to the cold dry air at altitude, bronchoconstriction, respiratory tract infection, AMS, vasomotor rhinitis or water loss from the respiratory tract. A plausible hypothesis is a transient overload of normal physiologic processes resulting from an imbalance between the increased production of transpulmonary filtrate due to elevated pulmonary artery pressures from intense exercise and hypoxia combined with a sudden reduction in the rate of lymph clearance due to the decrease in hyperpnea following the abrupt cessation of intense exercise. Clinical pulmonary edema results from a breakdown of normal homeostatic processes for removal of interstitial fluid; for individuals in this report, normal homeostatic processes were still operative. Regardless of the mechanism, this syndrome appears to be benign and when it occurs at altitude, it does not imply an increased risk of AMS or HAPE, does not require treatment and does not necessitate a restriction in activity or a prohibition against higher ascent. J Med Cases. 2013;4(5):323-326 doi: https://doi.org/10.4021/jmc1250e